用小波变换和多项式拟合提高地震资料分辨率

Improving seismic section resolution by wavelet transform and polynomial fitting

用小波变换研究了地震勘探信号小波变换的过零点特性。提出了用小波变换的过零点匹配提取地震勘探信号同相轴变化信息，并利用所提取信息和多项式拟合消除随机噪声，同时增强信号高频，使信号信噪比和分辨率都得到显著提高的新方法。该方法对地震道进行小波变换，对变换结果进行过零点匹配求出地震同相轴变化信息，沿同相轴对地震道的小波变换系数进行多项式拟合得到去噪的小波变换系数，对去噪后小波变换系数进行高频增强并进行反变换便得到具有高信噪比和高分辨率的地震道。理论分析和实际处理结果表明，该方法能有效地提高地震勘探信号的信噪比和分辨率。

A new method is presented to improve signal noise ratio and resolution of seismic section based on the properties of wavelet transform zero crossings and good correlation between reflected waves of neighbouring seismic traces. The properties of wavelet transform zero crossings are used to match two neighbouring seismic traces in order to obtain the varied information of reflector. According to the matched results, the coefficients of wavelet transforms are picked out to fit a polynomial. The noises are suppressed by use of the polynomial fitting method. The energy of high frequency components of seismic trace is strengthened , and the high resolution seismic traces are reconstructed from the filtered wavelet transform coefficients by use of the inverse wavelet transforms. The processing results have proved that this method can effectively improve signal noise ratio and resolution of seismic section.